(1) Field of the Invention
The present invention relates to a cooling structure for cooling a plurality of heating elements having different heights.
(2) Description of the Related Art
The miniaturization and high integration have been rapidly advanced for semiconductors used in electronic equipments, especially for semiconductors represented by CPUs of information processing equipments. Accordingly, the amount of heat generation has been increasing. However, as general characteristics of the semiconductors, there is the problem that the semiconductors are vulnerable to heat, and when the semiconductors are used at a high temperature, their reliability is significantly reduced. Therefore, in order to ensure the cooling performance of the semiconductors, the sizes of the heatsinks mounted on the semiconductors tend to be large as compared with the conventional ones.
Further, in recent years, along with the enhancement in the performance of CPUs, the amount of heat generation of the power supply components for stably supplying electric power to the components of the CPUs, especially MOS-FETs, regulator components, and the like which are mounted on the substrates have been dramatically increased. In general, a plurality of these components are mounted for each kinds of power supplies. The amount of heat generation of each component is small as compared with a CPU. However, since the component areas are very small, the heating density of these components is comparable to an LSI of several tens of watts. Further, in these components, the component temperature and the substrate temperature are substantially the same due to their mounting structure. Accordingly, cooling the power supply components becomes essential in order to ensure the reliability of the substrate.